Import key configuration error -- simple problem?
This is a change made in blender 2.72.

The select operator in the sequencer used to use a boolean value (True or False) to select before or after the current frame.

Now in 2.72 it can use 'NONE' 'LEFT' 'RIGHT' or 'MOUSE'. While the boolean values can be entered as True and False the enumerated values need to be in a quoted string.

I believe to get the closest match would be -

Find instances of

kmi.properties.left_right = True


and replace them with

kmi.properties.left_right = 'MOUSE'


and replace

kmi.properties.left_right = False


with

kmi.properties.left_right = 'NONE'


Of course you may want to experiment and adjust it as desired.